A Linear D. C. Restorer

This paper introduces a new concept in nuclear pulse filtering, that of using linear active feedback to accomplish a pulse manipulation which until now has been performed only by nonlinear methods. The linear method eliminates threshold effects and extends the circuit application to low level and to highly linear signals, without the inherent increase in noise produced by the nonlinear methods. A linear circuit has been constructed which performs the function of D. C. restoration. That is, pulses which occur randomly in time and have low frequency components which overlap to produce degradation of primary pulse information, may be clarified and separated by the circuit. The action is similar to the basic Robinson restorer except that no threshold or other nonlinearity is involved and no noise need be introduced. The results are otherwise comparable, and time of pulse recovery to 0.01% of signal level may be traded off against reduction of signal amplitude.